当前位置:主页 > 科技论文 > 环境工程论文 >

有机膨润土等离子体改性及其对典型VOCs的吸附性能研究

发布时间:2018-05-26 07:51

  本文选题:挥发性有机物 + 有机膨润土 ; 参考:《浙江工商大学》2015年硕士论文


【摘要】:近年来,中国的雾霾问题受到了广泛关注。研究发现二次有机气溶胶是形成雾霾的重要因素,而挥发性有机物(VOCs)的排放则是形成二次有机气溶胶的主要原因。因此,VOCs治理势在必行。吸附法是VOCs治理过程中应用最为广泛的方法。然而,常用的吸附剂如活性炭存在再生难度大、吸附成本高、伴随二次污染等问题。煅烧后的有机膨润土(PCH-calcination)是一种对VOCs具有良好吸附作用的吸附剂,然而其制备过程能耗高、耗时长,易导致有机膨润土层间和孔道塌陷影响其吸附性能。因此,本文在有机膨润土传统煅烧制备方法的基础上,重点研究了有机膨润土等离子体改性的新型制备方法。首先研究了PCH-calcination对典型VOCs的吸附性能,优化有机膨润土制备方法,为等离子体改性奠定研究基础;之后重点研究了等离子体放电参数和放电条件对有机膨润土改性效果的影响,并从物化特性对改性机理进行了深入的分析。研究结果表明PCH-calcination的吸附性能跟阳离子表面活性剂的碳链长度有关,十六烷基三甲基溴化铵(CTMAB)制备的有机膨润土在煅烧后比表面积达到608.3 m2/g,对环己酮的吸附量达到129mg/g; PCH-calcination的吸附性能与阳离子表面活性剂的添加量呈正相关,然而当膨润土与阳离子表面活性剂的配比≥1:2时,环己酮吸附量提高不明显;PCH-calcination对环己酮的吸附性能与制备过程中柱撑剂的添加量有关,当柱撑剂与膨润土的配比在1:120时,其煅烧后对环己酮的吸附量最大。另外,研究结果表明吸附温度越高,PCH-calcination对环己酮的吸附量越小;初始吸附速率随着环己酮流量的增大而增加;PCH-calcination对环己酮的吸附量随着环己酮浓度增加而增加。综上所述,本实验优选出有机膨润土的制备方法和吸附方法为:CTMAB配比为1:1,柱撑剂配比为1:120,动态吸附过程中温度为30℃,环己酮流量为500 mL/min,环己酮浓度为20 mg/m3。此方法作为等离子体改性有机膨润土及其吸附性能研究的基本条件。在等离子体改性有机膨润土过程中,放电时间、放电间隙、初始放电电压和正负电晕等放电参数都会影响有机膨润土的吸附性能。研究结果表明等离子体改性后的有机膨润土(PCH-plasma)吸附性能随着放电时间的增加先增加而后减小,放电时间从1h增加至8 h,环己酮吸附量从40 mg/g上升至132 mg/g,而10h时其吸附量下降至123 mg/g。究其原因是由于PCH-plasma的比表面积和介孔孔容随着放电时间先增加而后减少,比表面积从153.5 m2/g增加至468.8 m2/g后又减少至405.0 m2/g,孔容从0.28 cm3/g增大至0.75 cm3/g后又减少至0.62cm3/g。XPS的结果显示PCH-plasma中碳、氧以及C=OR等官能团对其吸附性能起到关键作用;放电间隙从5 mm增加至15mm, PCH-plasma对环己酮的吸附性能变好;初始放电电压与PCH-plasma的吸附性能呈正相关;而负电晕的改性效果稍好于正电晕。此外,本文还研究了氧气浓度和流量、有机膨润土的处理量等参数对PCH-plasma吸附性能的影响,结果显示较高的氧气浓度有利于有机膨润土的改性,当氧气浓度为20%时PCH-plasma对环己酮吸附量为12 mg/g,比表面积和孔容分别为142.8m2/g和0.35 cm3/g,而当氧气浓度上升至100%时,吸附量提高到69 mg/g,比表面积和孔容分别增加至342.8 m2/g和0.50 cm3/g; PCH-plasma吸附性能随着氧气流量的增加而改善;有机膨润土的处理量越小,有机膨润土的改性效果越好,但太小也可能导致有机膨润土无法在改性过程发生燃烧而使得改性效果变差。从上述结果可知,在本实验中,放电时间为8h时PCH-plasma对环己酮的吸附量为.132 mg/g,达到甚至超过了煅烧后有机膨润土对环己酮的吸附量。
[Abstract]:In recent years, the haze problem in China has been widely concerned. Two organic aerosols are found to be an important factor in the formation of fog and haze, and the emission of volatile organic compounds (VOCs) is the main reason for the formation of two organic aerosols. Therefore, the treatment of VOCs is imperative. Adsorption is the most widely used method in the process of VOCs treatment. The commonly used adsorbents, such as activated carbon, are difficult to regenerate, with high adsorption cost and two pollution. The calcined organic bentonites (PCH-calcination) are a kind of adsorbents with good adsorption to VOCs. However, the preparation process has high energy consumption and long time consumption, and the easy conductivity of organic bentonite interlayer and pore collapse affects its adsorption. Therefore, on the basis of the traditional calcining methods of organic bentonite, this paper focuses on the new preparation methods of plasma modification of organic bentonite. Firstly, the adsorption properties of PCH-calcination on typical VOCs are studied, and the preparation methods of organic bentonite are optimized, and the research foundation for plasma modification is laid. The effects of plasma discharge parameters and discharge conditions on the modification of organic bentonite were investigated, and the modification mechanism was deeply analyzed from physicochemical properties. The results showed that the adsorption properties of PCH-calcination were related to the carbon chain length of the cationic surfactant, and the organic bentonite prepared by sixteen alkyl three methyl ammonium bromide (CTMAB) was found. After calcined, the specific surface area reached 608.3 m2/g and the adsorption capacity of cyclohexanone reached 129mg/g; the adsorption performance of PCH-calcination was positively related to the addition of cationic surfactant. However, when the ratio of bentonite to cationic surfactant was more than 1:2, the adsorption capacity of cyclohexanone was not obviously improved; the adsorption of cyclohexanone by PCH-calcination The performance is related to the addition of pillared agent in the preparation process. When the ratio of pillared and bentonite is 1:120, the adsorption capacity of cyclohexanone after calcining is the largest. In addition, the results show that the higher the adsorption temperature, the smaller the adsorption capacity of PCH-calcination to cyclohexanone; the initial adsorption rate increases with the increase of cyclohexanone flow rate; PCH-c The adsorption of cyclohexanone with alcination increases with the concentration of cyclohexanone. In summary, the preparation and adsorption methods of organic bentonite are: CTMAB ratio is 1:1, the ratio of pillared agent is 1:120, the temperature of the dynamic adsorption process is 30, the flow of cyclohexanone is 500 mL/min, the concentration of cyclohexanone is 20 mg/m3.. As the basic conditions for the study of the plasma modified organic bentonite and its adsorption properties, the discharge time, discharge gap, initial discharge voltage and positive and negative corona will affect the adsorption properties of organic bentonite during the process of plasma modified organic bentonite. The results show that the organic bentonite after the plasma is modified. The adsorption performance of soil (PCH-plasma) increases first and then decreases with the discharge time, and the discharge time increases from 1H to 8 h, and the adsorption amount of cyclohexanone increases from 40 mg/g to 132 mg/g, while the adsorption amount of 10h decreases to 123 mg/g., due to the specific surface area of PCH-plasma and the first increase and then then decrease of the mesoporous Kong Kongrong with the discharge time. The area increased from 153.5 m2/g to 468.8 m2/g and decreased to 405 m2/g. Kong Rong increased from 0.28 cm3/g to 0.75 cm3/g and decreased to 0.62cm3/g.XPS. The results showed that the functional groups such as carbon, oxygen and C=OR played a key role in the adsorption properties of PCH-plasma; the discharge gap increased from 5 mm to 15mm and PCH-plasma on cyclohexanone. The initial discharge voltage has a positive correlation with the adsorption performance of PCH-plasma, while the modified effect of negative corona is slightly better than the Yu Zheng corona. In addition, the effects of oxygen concentration and flow rate and the amount of organic bentonite on the adsorption properties of PCH-plasma are also studied. The results show that the higher oxygen concentration is beneficial to the modification of organic bentonite. When the oxygen concentration is 20%, the adsorption capacity of cyclohexanone is 12 mg/g, and the specific surface area and pore volume are 142.8m2/g and 0.35 cm3/g, respectively. When the oxygen concentration increases to 100%, the adsorption capacity increases to 69 mg/g, and the surface area and pore volume increase to 342.8 m2/g and 0.50 cm3/g, respectively. The adsorption performance of PCH-plasma increases with the increase of oxygen flow. Improvement; the smaller the amount of organic bentonite treatment, the better the modification effect of organic bentonite, but too small also may cause the organic bentonite to be unable to burn in the modification process and make the modification effect worse. From the above results, the adsorption amount of PCH-plasma to cyclohexanone at 8h discharge time is.132 mg/g, even in this experiment. The adsorption capacity of organic bentonite to cyclohexanone after calcination exceeded.
【学位授予单位】:浙江工商大学
【学位级别】:硕士
【学位授予年份】:2015
【分类号】:TQ424.3;X51

【相似文献】

相关期刊论文 前10条

1 ;海名斯新建有机膨润土厂[J];中国涂料;2002年05期

2 余丽秀,孙亚光;分散性有机膨润土评价方法研究[J];非金属矿;2004年03期

3 宋美宁,吕宪俊;有机膨润土的制备工艺及应用现状研究[J];中国非金属矿工业导刊;2005年04期

4 李凯,龚文琪;有机膨润土的制备及应用综述[J];科技创业月刊;2005年02期

5 罗太安;;有机膨润土对活性艳红X-3B的吸附[J];化工矿物与加工;2006年10期

6 王骞;王玉娇;梁成刚;;颗粒有机膨润土的制备及脱色研究[J];阴山学刊(自然科学);2011年02期

7 陈芸;;有机膨润土的应用[J];建材工业信息;1985年02期

8 陈来申;;有机膨润土凝胶在防锈底漆中的应用[J];江苏化工;1987年03期

9 徐文e,

本文编号:1936406


资料下载
论文发表

本文链接:https://www.wllwen.com/kejilunwen/huanjinggongchenglunwen/1936406.html


Copyright(c)文论论文网All Rights Reserved | 网站地图 |

版权申明:资料由用户20ebe***提供,本站仅收录摘要或目录,作者需要删除请E-mail邮箱bigeng88@qq.com